The purpose of this protocol is to examine the effect of chronic sustained hyperinsulinemia on glucose phosphorylation and transport in forearm muscle. It has been previously demonstrated that chronic hyperinsulinemia induces insulin resistance in normal subjects, but the basic cellular mechanisms are unknown. The triple tracer technique developed by this investigative team has demonstrated that acute physiologic hyperinsulinemia stimulates both glucose transport and glucose phosphorylation, two early, key, insulin-regulated steps. The protocol will elucidate the defect in muscle glucose transport in NIDDM.